Information recording medium, information recording method, information recording apparatus, information reproduction method, and information reproduction apparatus

ABSTRACT

According to a recording method for a conventional rewritable disc, the latest data is recorded by rewriting data in an identical area. In the case of a disc of which the number of times of data rewrite is limited, this causes a problem that a defect block is easily generated. The present invention has an objective of providing an information recording medium, an information recording and reproduction method, and an information recording and reproduction system apparatus, by which data is recorded sequentially from an unallocated area after an entry sector number, and data recording is sequentially repeated from an inner portion to an outer portion.

TECHNICAL FIELD

[0001] The present invention relates to an information recording medium,of which the number of times data can be rewritten in the same area islimited, a method and an apparatus for recording information on such aninformation recording medium, and a method and an apparatus forreproducing information recorded on such an information recordingmedium.

BACKGROUND ART

[0002] One exemplary information recording medium having a sectorstructure is an optical disc. As the density and capacity of the opticaldisc have recently been increased and more and more information has beentransferred by multimedia, video and audio data are now enjoyedinteractively using a plurality of strings of data recorded on anoptical disc. A disc, having interactive video data recorded thereon,has an AV file including a plurality of MPEG streams as well as acontrol file for controlling reproduction of AV data recorded thereon.

[0003] Hereinafter, with reference to FIG. 8 illustrating a directorystructure, the relationship of an AV directory structure and an AV filewith a control file will be described. An AV directory at which videoand audio data is recorded is located under a root directory. The AVdirectory has AV files (AVfile-a), (AVfile-c) and (AVfile-d) includingthe video and audio data itself, and a control file (Datafile) includinginformation regarding the AV files. The control file (Datafile)includes, for example, names of titles of video and audio data recordedon the disc, the order of reproduction of data strings of each title,and positional information of I picture, P picture and the like whichare necessary for special reproduction such slow reproduction,fast-forwarding and the like. In the case where one control filecorresponds to one AV file, a plurality of control files may berecorded. The files are recorded under a predetermined directory withpredetermined file names, such that the recording and reproductionapparatus can easily access an intended file.

[0004] With reference to FIG. 21, one exemplary data structure of aDVD-RAM disc, which is a rewritable disc, having the above-describedfiles recorded thereon using a volume file structure defined in theECMA167 Standards will be described. An upper portion of the figurecorresponds to an inner area of the disc, and a lower portion of thefigure corresponds to an outer area of the disc. Logical sector numbersare allocated from the leading end of the volume space in units of asector. A volume structure area 101 has information recorded therein forlogically handling the disc as a volume, and also has positionalinformation of a space bit map 1021 and positional information of a fileentry 1022 of a root directory. In general, each file is accessed usinga logical block number, but in this example, each file is accessed usinga logical sector number for simplicity of explanation.

[0005] A file structure area 1001 is an area in which a descriptor fordefining a file structure is to be recorded. The space bit map 1021 is abit map for managing, in units of a sector, an unallocated area of thevolume space to which a file structure or data can be allocated. Thespace bit map 1021 has information indicating, in units of a logicalsector, whether each area has information already recorded therein orunallocated. The file entry (root directory) 1022 has attributeinformation and recording position information of a root directory. Aroot directory 1023 has positional information of an file entry 1024 ofan AV directory (AVDir) recorded under the root directory.

[0006] The file entry (AVDir) 1024 has attribute information andrecording position information of an AV directory (AVDir) 1025. The AVdirectory (AVDir) 1025 has positional information of file entries 1026,1027, 1028 and 1029 respectively of an AV file (AVfile-a), an AV file(AVfile-c), an AV file (AVfile-d) and a control file (Datafile).

[0007] These file entries of the AV files and the control file haveattribute information and positional information of the AV file(AVfile-a), the AV file (AVfile-c), the AV file (AVfile-d) and thecontrol file (Datafile) 1030 which are recorded in a file area 1002. Thefile area 1002 is an area in which data of the AV files and the controlfile is to be recorded.

[0008] A defect management area 1003 includes a DMA (Defect ManagementArea) 1004 for managing a defect and a spare area 1005 in which thecontent of the data which is to be recorded in the defect area issubstitutively recorded. In the DMA, a spare entry for managing a defectarea which is substituted for and an area for substituting for thedefect area is registered. The spare entry has an address 1045 of thedefect area and an address 1046 of the spare area.

[0009] Next, with reference to FIG. 22 illustrating a block diagram andFIG. 23 illustrating a flowchart, a process for writing new video andaudio data over the AV file (AVfile-d) will be described. Here, the sizeof the video and audio data to be newly written is larger than the sizeof the video and audio data already recorded in the AV file (AVfile-d).

[0010] (S1201) A system control section 201 follows a control programbuilt therein as file structure reproduction means 110 so as to acquirepositional information of an unallocated area corresponding to the sizethat the AV file (AVfile-d) is short of, and necessary for, writing thenew video and audio data from the space bit map 1021.

[0011] (S1202) The system control section 201 follows a control programbuilt therein as file recording means 213 so as to overwrite the data inthe AV file (AVfile-d), and instructs an optical disc drive device 205to record data in the unallocated area acquired in step (S1201). Theoptical disc drive device 205 records the video and audio datatransferred from a data memory 221 and writes the relevant control dataover the data in the control file (Datafile). When a defect area isdetected during the file recording processing, the optical disc drivedevice 205 substitutively records the content of the AV file, which isto be recorded in a defect area 1053, in the spare area 1005, andregisters, in the DMA 1004, a spare entry 1051 which is informationcorresponding to an address 1045 of the defect area 1053 and an address1046 of the spare area 1005. The optical disc drive device 205 notifiesthe system control section 201 of the completion of the recordingoperation.

[0012] (S1203) The system control section 201 follows a control programbuilt therein as file structure recording means 1101 so as to reflectthe recording state of the unallocated area, used in step (S1202), inthe space bit map 1021.

[0013] (S1204) The system control section 201 follows a control programbuilt therein as the file structure recording means 1101 so as toinstruct the optical disc drive device 205 to record in the filestructure area 1001 the updated space bit map 1021, the file entry(Datafile) 1029 of the control file (Datafile) 1030, and the file entry(AVfile-d) 1028 of the recorded AV file. The optical disc drive device205 writes such file structures transferred from a file structure memory1103 over the data in the file structure area, and notifies the systemcontrol section 201 of the completion of the recording operation.

[0014] In the above example of substituting for a defect area, the AVfile is overwritten. The substituting is similarly performed forrecording a data file such as a control file, a volume structure or afile structure.

[0015] In a lead-in area of the DVD-RAM disc, four data structure areaDMAs (Defect Management Areas) for defect management performed in asector in the volume space are provided. All such DMAs are rewritten atthe corresponding position each time a defect occurs.

[0016] For simplicity of explanation, the spare area is located in thelead-in area in the above example. In an actual DVD-RAM disc, however, aspare area is provided between the lead-in area and the volume space. Inthe case where there is a shortage of the spare area due to frequentoccurrence of substitution, an additional spare area is provided in anarea external to the volume space.

[0017] In the case of a rewritable disc in which data can be rewrittenin the same sector 100,000 times, no problem occurs even if data isconcentratedly rewritten in the same sector. In the case of a rewritabledisc to which the number of times data can be rewritten is limited toabout 100 to 1000 times, however, the following problems occur when theuser newly creates, rewrites, or deletes a file: since data isfrequently written in the same area, defects easily occur as a result ofwhich important data, such as a file structure or a control file, isdestroyed, or data cannot be recorded on the medium.

[0018] The present invention for solving the above-described problemshas an objective of sequentially moving an AV file area and a basic filestructure area from an inner portion to an outer portion of a disc towhich the number of times of data rewrite is limited, so as to avoidconcentration of data rewrite in the same area and thus preventoccurrence of a defect.

DISCLOSURE OF THE INVENTION

[0019] An information recording medium, according to the presentinvention, to which the number of times of data rewrite to an identicalarea is limited includes a first information recording area to whichdata is recordable by sequential loop recording; and a secondinformation recording area. The first information recording areaincludes a plurality of blocks. Each of the plurality of blocks includesan area for recording version information indicating a version of theblock and an area for recording pointer information indicating aposition of the second information recording area. Pointer informationcorresponding to latest version information is used as valid pointerinformation. Thus, the above-described objectives are achieved.

[0020] The second information recording area may be an area in whichdata is recordable by sequential loop recording.

[0021] An information recording medium, according to the presentinvention, to which the number of times of data rewrite to an identicalarea is limited includes a plurality of first information recordingareas in which data is recordable by sequential loop recording; a secondinformation recording area; and a third information recording area forrecording identification information indicating which one of theplurality of first information recording areas is valid. Each of theplurality of first information recording areas includes a plurality ofblocks. Each of the plurality of blocks includes an area for recordingversion information indicating a version of the block and an area forrecording pointer information indicating a position of the secondinformation recording area. The pointer information corresponding tolatest version information is used as valid pointer information. Thus,the above-described objectives are achieved.

[0022] The identification information may be rewritten in a specificarea of the third information recording area. When recording to thespecific area becomes impossible, the identification information may berewritten in an area in the third information recording area other thanthe specific area.

[0023] The third information recording area may be an area in which datais recordable by sequential loop recording. The third informationrecording area may include a plurality of blocks. Each of the pluralityof blocks may include an area for recording version informationindicating a version of the block. The identification informationcorresponding to latest version information may be used as valididentification information.

[0024] An information recording method, according to the presentinvention, for recording information on an information recording mediumof which the number of times of data rewrite to an identical area islimited is provided. The information recording medium includes a firstinformation recording area to which data is recordable by sequentialloop recording, and a second information recording area. The firstinformation recording area includes a plurality of block. Theinformation recording method includes the steps of designating one ofthe plurality of blocks; and recording, in the designated block, versioninformation indicating a version of the designated block and pointerinformation indicating a position of the second information recordingarea. Pointer information corresponding to latest version information isused as valid pointer information. Thus, the above-described objectivesare achieved.

[0025] An information recording method, according to the presentinvention, for recording information on an information recording mediumof which the number of times of data rewrite to an identical area islimited is provided. The information recording medium includes aplurality of first information recording areas in which data isrecordable by sequential loop recording, a second information recordingarea, and a third information recording area. Each of the plurality offirst information recording areas includes a plurality of blocks. Theinformation recording method includes the steps of recording, in thethird information recording area, identification information indicatingwhich one of the plurality of first information recording areas isvalid; designating one of the plurality of blocks included in the validfirst information recording area; and recording, in the designatedblock, version information indicating a version of the designated blockand pointer information indicating a position of the second informationrecording area. Pointer information corresponding to latest versioninformation is used as valid pointer information. Thus, theabove-described objectives are achieved.

[0026] An information recording apparatus, according to the presentinvention, for recording information on an information recording mediumof which the number of times of data rewrite to an identical area islimited is provided. The information recording medium including a firstinformation recording area to which data is recordable by sequentialloop recording, and a second information recording area. The firstinformation recording area includes a plurality of blocks. Theinformation recording apparatus includes means for designating one ofthe plurality of blocks; and means for recording, in the designatedblock, version information indicating a version of the designated blockand pointer information indicating a position of the second informationrecording area. Pointer information corresponding to latest versioninformation is used as valid pointer information. Thus, theabove-described objectives are achieved.

[0027] An information recording apparatus, according to the presentinvention, for recording information on an information recording mediumof which the number of times of data rewrite to an identical area islimited is provided. The information recording medium includes aplurality of first information recording areas in which data isrecordable by sequential loop recording, a second information recordingarea, and a third information recording area. Each of the plurality offirst information recording areas includes a plurality of blocks. Theinformation recording apparatus includes means for recording, in thethird information recording area, identification information indicatingwhich one of the plurality of first information recording areas isvalid; means for designating one of the plurality of blocks included inthe valid first information recording area; and means for recording, inthe designated block, version information indicating a version of thedesignated block and pointer information indicating a position of thesecond information recording area. Pointer information corresponding tolatest version information is used as valid pointer information. Thus,the above-described objectives are achieved.

[0028] An information reproduction method, according to the presentinvention, for reproducing information recorded on an informationrecording medium of which the number of times of data rewrite to anidentical area is limited is provided. The information recording mediumincludes a first information recording area to which data is recordableby sequential loop recording, and a second information recording area.The first information recording area includes a plurality of blocks. Inat least one of the plurality of blocks, version information indicatinga version of the block and pointer information indicating a position ofthe second information recording area are recorded. The informationreproduction method includes the steps of designating one of theplurality of blocks; and determining whether or not to acquire thepointer information recorded in the designated block in accordance withthe version information recorded in the designated block. Pointerinformation corresponding to latest version information is used as validpointer information. Thus, the above-described objectives are achieved.

[0029] An information reproduction method, according to the presentinvention, for reproducing information recorded on an informationrecording medium of which the number of times of data rewrite to anidentical area is limited is provided. The information recording mediumincludes a plurality of first information recording areas in which datais recordable by sequential loop recording, a second informationrecording area, and a third information recording area. Each of theplurality of first information recording areas includes a plurality ofblocks. In at least one of the plurality of blocks, version informationindicating a version of the block and pointer information indicating aposition of the second information recording area are recorded. In thethird information recording area, identification information indicatingwhich one of the plurality of first information recording areas is validis recorded. The information reproduction method includes the steps ofacquiring the identification information from the third informationrecording area; designating one of the plurality of blocks included inthe valid first information recording area which is indicated by theidentification information; and determining whether or not to acquirethe pointer information recorded in the designated block in accordancewith the version information recorded in the designated block. Pointerinformation corresponding to latest version information is used as validpointer information. Thus, the above-described objectives are achieved.

[0030] An information reproducing apparatus, according to the presentinvention, for reproducing information recorded on an informationrecording medium of which the number of times of data rewrite to anidentical area is limited is provided. The information recording mediumincludes a first information recording area to which data is recordableby sequential loop recording, and a second information recording area.The first information recording area includes a plurality of blocks. Inat least one of the plurality of blocks, version information indicatinga version of the block and pointer information indicating a position ofthe second information recording area are recorded. The informationreproduction apparatus includes means for designating one of theplurality of blocks; and means for determining whether or not to acquirethe pointer information recorded in the designated block in accordancewith the version information recorded in the designated block. Pointerinformation corresponding to latest version information is used as validpointer information. Thus, the above-described objectives are achieved.

[0031] An information reproduction apparatus, according to the presentinvention, for reproducing information recorded on an informationrecording medium of which the number of times of data rewrite to anidentical area is limited is provided. The information recording mediumincludes a plurality of first information recording areas in which datais recordable by sequential loop recording, a second informationrecording area, and a third information recording area. Each of theplurality of first information recording areas includes a plurality ofblocks. In at least one of the plurality of blocks, version informationindicating a version of the block and pointer information indicating aposition of the second information recording area are recorded. In thethird information recording area, identification information indicatingwhich one of the plurality of first information recording areas is validis recorded. The information reproduction apparatus includes means foracquiring the identification information from the third informationrecording area; means for designating one of the plurality of blocksincluded in the valid first information recording area which isindicated by the identification information; and means for determiningwhether or not to acquire the pointer information recorded in thedesignated block in accordance with the version information recorded inthe designated block. Pointer information corresponding to latestversion information is used as valid pointer information. Thus, theabove-described objectives are achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032]FIG. 1 shows a data structure of an information recording mediumaccording to Example 1.

[0033]FIG. 2 is a block diagram illustrating a structure of aninformation recording and reproduction apparatus according to Example 1.

[0034]FIG. 3 is a flowchart illustrating a procedure of formattingprocessing in Example 1.

[0035]FIG. 4 shows a data structure of an information recording mediumafter the formatting processing is performed in Example 1.

[0036]FIG. 5 is a flowchart illustrating a procedure of file recordingprocessing in Example 1.

[0037]FIG. 6 shows a data structure of an information recording mediumafter the file recording is performed in Example 1.

[0038]FIG. 7 is a flowchart illustrating a procedure of filereproduction processing in Example 1.

[0039]FIG. 8 shows a directory structure for managing a file recorded ona disc.

[0040]FIG. 9 shows a data structure of a recording information zone inExample 1.

[0041]FIG. 10 shows a data structure of an information recording mediumhaving a plurality of entry sector numbers in Example 1.

[0042]FIG. 11 shows a data structure of an information recording mediumaccording to Example 2.

[0043]FIG. 12 shows a data structure of an information recording mediumafter substitution processing to a unit is performed in Example 2.

[0044]FIG. 13 is a flowchart illustrating a procedure of file recordingprocessing in Example 2.

[0045]FIG. 14 is a flowchart illustrating a procedure of filereproduction processing in Example 2.

[0046]FIG. 15 shows a data structure of an information recording mediumaccording to Example 3.

[0047]FIG. 16 is a flowchart illustrating a procedure of file recordingprocessing in Example 3.

[0048]FIG. 17 shows a data structure of an information recording mediumaccording to Example 4.

[0049]FIG. 18 is a flowchart illustrating a procedure of file recordingprocessing in Example 4.

[0050]FIG. 19 shows a data structure of an information recording mediumaccording to Example 5.

[0051]FIG. 20 is a flowchart illustrating a procedure of updateprocessing of an entry sector number in Example 5.

[0052]FIG. 21 shows a data structure of a conventional DVD-RAM disc.

[0053]FIG. 22 is a block diagram illustrating a structure of aninformation recording and reproduction apparatus using a conventionalDVD-RAM disc.

[0054]FIG. 23 is a flowchart illustrating a procedure of conventionalfile recording processing.

BEST MODE FOR CARRYING OUT THE INVENTION

[0055] (Definition of Terms)

[0056] The terms used in this specification will be defined as follows.

[0057] (1) “Sequential loop recording” refers to searching forunallocated areas in a predetermined recording area, allocating theareas based on the search result, and recording data in the allocatedareas. Searching for unallocated areas in the predetermined recordingarea is achieved by searching for an unallocated area in a certaindirection from a predetermined position and, in the case where thesearch reaches the trailing end of the predetermined recording area,searching for the next unallocated area from the leading end of thepredetermined recording area. In this specification, “sequential looprecording” is also referred to as “loop recording in a certaindirection”. These terms are synonymous.

[0058] (2) “AV data” refers to data indicating at least one of videodata and audio data.

[0059] (3) An “AV file” refers to a file including AV data.

[0060] 1. EXAMPLE 1

[0061] In Example 1, an information recording medium, of which thenumber of times data can be rewritten in the same area is limited, amethod and an apparatus for recording information on such an informationrecording medium, and a method and an apparatus for reproducinginformation recorded on such an information recording medium will bedescribed.

[0062] This example assumes an information recording medium to which thenumber of times data can be rewritten is limited to about 100 to 1000times. The present invention is also applicable to an informationrecording medium to which the number of times data can be rewritten islimited to a smaller number of times or a larger number of times. Theinformation recording medium may be, for example, any type ofinformation recording medium (for example, an optical disc, a magneticdisc, or a magneto-optical disc). In this example, the informationrecording medium is an optical disc.

[0063] In this example, information to be recorded on the informationrecording medium or information to be reproduced from the informationrecording medium is a file managed using a file structure based on theUDF (Universal Disk Format) conforming to the ECMA167 Standards.

[0064] In the following description, a descriptor, a pointer and thelike which are recorded on the information recording medium as a volumefile structure have a data structure defined by the ECMA167 or UDF(Universal Disk Format) Standards unless otherwise described in detail.

[0065] 1.1 Data Structure of an Optical Disc

[0066]FIG. 1 shows an exemplary data structure of an optical disc.

[0067] The optical disc has a lead-in area, a volume space, and alead-out area formed thereon. The lead-in area is provided in an innerportion of the optical disc. The lead-out area is provided in an outerportion of the optical disc. The volume space is interposed between thelead-in area and the lead-out area.

[0068] The lead-in area has a recording information zone 111 allocatedthereto. The recording information zone 111 includes a count unit and aplurality of registration units.

[0069] The volume space has a volume structure area 101, a latest filestructure area 131, and AV file areas 102, 103 and 105 allocatedthereto. Unallocated areas 121, 122, 124 and 125 are areas having novalid data allocated thereto.

[0070] The lead-out area has an extended recording information zone 112allocated thereto.

[0071] 1.2 Structure of an Information Recording and ReproductionApparatus

[0072]FIG. 2 shows an exemplary information recording and reproductionapparatus.

[0073] The information recording and reproduction apparatus includes asystem control section 201, a memory circuit 202, a magnetic disc device204, and an optical disc drive device 205. These elements are connectedto each other via an I/O bus 203.

[0074] The system control section 201 includes volume structurerecording means 211 for recording a volume structure, volume structurereproduction means 214 for reproducing the volume structure, VATstructure recording means 212 for recording a VAT structure, VATstructure reproduction means 215 for reproducing the VAT structure,space management structure recording means 251 for recording a spacemanagement structure, space management structure reproduction means 252for reproducing the space management structure, basic file structurerecording means 261 for recording a basic file structure, basic filestructure reproduction means 262 for reproducing the basic filestructure, file recording means 213 for recording file data, filereproduction means 216 for reproducing the file data, and defect areamanagement means 217. The system control section 201 is implemented by,for example, a microprocessor including a control program and anarithmetic memory.

[0075] The memory circuit 202 includes a data memory 221 for temporarilystoring a file, a VAT structure memory 222 used for arithmetic ortemporary storage of the VAT structure, a space management structurememory 253 used for arithmetic or temporary storage of the spacemanagement structure, a basic file structure memory 263 used forarithmetic or temporary storage of the basic file, a volume structurememory 223 used for arithmetic or temporary storage of the volumestructure, and a defect list memory 224.

[0076] The optical disc drive device 205 includes a drive controlsection 231, a memory circuit 232, and recording and reproduction means234. These elements are connected to each other via an internal bus 233.

[0077] The drive control section 231 includes recording information zonerecording means 271 for recording information in the recordinginformation zone, and recording information zone reproduction means 272for reproducing information recorded in the recording information zone.

[0078] The memory circuit 232 includes a recording information zonememory 273 used for arithmetic or temporary storage of the informationto be recorded in the recording information zone, and a buffer memory241.

[0079] The recording and reproduction means 234 records information onan optical disc 235 or reproduces information recorded on the opticaldisc 235.

[0080] The information recording and reproduction apparatus shown inFIG. 2 has both a function of recording information on the optical disc235 and a function of reproducing information recorded on the opticaldisc 235. Accordingly, the information recording and reproductionapparatus shown in FIG. 2 can be regarded as an “information recordingapparatus” for recording information on the optical disc 235. In thiscase, the elements which are not relevant to the function of recordinginformation on the optical disc 235 may be omitted. Alternatively, theinformation recording and reproduction apparatus shown in FIG. 2 can beregarded as an “information reproduction apparatus” for reproducinginformation recorded on the optical disc 235. In this case, the elementswhich are not relevant to the function of reproducing informationrecorded on the optical disc 235 may be omitted.

[0081] 1.3 Formatting Processing

[0082]FIG. 3 shows a procedure of formatting processing for formattingthe optical disc 235. The formatting processing is performed by theinformation recording and reproduction apparatus shown in FIG. 2.Hereinafter, the steps shown in FIG. 3 will be described in detail.

[0083] (S301) The system control section 201 creates a volume structureincluding pre-designated parameters such as a volume name, and storesthe volume structure in the volume structure memory 223 of the memorycircuit 202. The system control section 201 further instructs theoptical disc drive device 205 to record the volume structure, stored inthe volume structure memory 223, on the optical disc 235. Theabove-described operations of the system control section 201 areachieved by, for example, executing a control program built in thesystem control section 201 as the volume structure recording means 211.The optical disc drive device 205 records the volume structure at apredetermined position of the optical disc 235, and when the recordingoperation is completed, notifies the system control section 201 of thecompletion of the recording operation.

[0084] (S302) The system control section 201 creates a basic filestructure, and stores the basic file structure in the basic filestructure memory 263 of the memory circuit 202. The system controlsection 201 further instructs the optical disc drive device 205 torecord the basic file structure, stored in the basic file structurememory 263, on the optical disc 235. The above-described operations ofthe system control section 201 are achieved by, for example, executing acontrol program built in the system control section 201 as the basicfile structure recording means 261. The optical disc drive device 205records the basic file structure at a predetermined position of theoptical disc 235, and when the recording operation is completed,notifies the system control section 201 of the completion of therecording operation.

[0085] (S303) The system control section 201 creates a space managementstructure, and stores the space management structure in the spacemanagement structure memory 253 of the memory circuit 202. At thispoint, positional information of an unallocated area 422 is registeredin a space entry 453 in consideration of the capacity of the VATstructure area allocated in step (S304). The system control section 201further instructs the optical disc drive device 205 to record the spacemanagement structure, stored in the space management structure memory253, on the optical disc 235. The above-described operations of thesystem control section 201 are achieved by, for example, executing acontrol program built in the system control section 201 as the spacemanagement structure recording means 251. The optical disc drive device205 records the space management structure at a predetermined positionof the optical disc 235, and when the recording operation is completed,notifies the system control section 201 of the completion of therecording operation.

[0086] (S304) The system control section 201 creates a VAT structure,and stores the VAT structure in the VAT structure memory 222 of thememory circuit 202. The system control section 201 further instructs theoptical disc drive device 205 to record the VAT structure, stored in theVAT structure memory 222, on the optical disc 235. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as the VAT structure recording means 212. The optical disc drivedevice 205 records the VAT structure at a predetermined position of theoptical disc 235, and when the recording operation is completed,notifies the system control section 201 of the completion of therecording operation.

[0087] (S305) The system control section 201 instructs the optical discdrive device 205 to record data in the recording information zone. Thedrive control section 231 creates a first registration block 176including an entry sector number (pointer information) indicating theposition of the trailing end of the latest file structure area and aversion number (version information) for identifying a validregistration block, stores the first registration block 176 in therecording information zone memory 273 of the memory circuit 232, andrecords the first registration block 176 at a predetermined position ofthe optical disc 235. For example, the drive control section 231 recordsthe first registration block 176 in a first registration unit 142, andrecords, at the leading end of the count unit, the count block havingthe identification number of the registration unit in which data hasbeen recorded. The above-described operations of the drive controlsection 231 are achieved by, for example, executing a control programbuilt in the drive control section 231 as the recording information zonerecording means 271. When the recording operation is completed, theoptical disc drive device 205 notifies the system control section 201 ofthe completion of the recording operation.

[0088] In this example, the recording operation of the registrationblock and the recording operation of the count block are performedseparately, but these recording operations may be performedconcurrently.

[0089]FIG. 4 shows a structure of data recorded on the optical disc 235after the formatting processing is performed.

[0090] The volume structure area 101 has the volume structure recordedtherein. The volume structure includes a volume recognition sequence 441having recognition information of a volume, a primary volume descriptor442 having attribute information of the volume, a processing systemdescriptor 443 having information for the processing system, a partitiondescriptor 444 having partition information, a logical volume descriptor445 having recognition information of a logical volume, an unallocatedspace descriptor 446 having information of an unallocated area in thevolume space, an terminating descriptor 447 indicating a trailing end ofa basic descriptor sequence, a logical volume integrity descriptor 448having information of an integrity state of the logical volume, and ananchor volume descriptor pointer 449 having information on access startto the volume. The information recorded in the volume structure area isnot limited to the above-described order or types.

[0091] In a basic file structure area 432 of a latest file structurearea 431, the basic file structure is recorded. The basic file structureincludes a file set descriptor 450, a root directory 451, and a fileentry (root directory) 452.

[0092] In a space management structure area 421 of the latest filestructure area 431, the space management structure is recorded. Thespace management structure includes the unallocated space entry 453.

[0093] In a VAT structure area 401 of the latest file structure area431, the VAT structure is recorded. The VAT structure includes a VAT 454and a VATICB 455. The VAT 454 and the VATICB 455 are data structuresdefined by the UDF Standards. A recording position of data on an opticaldisc is indicated using a virtual address in a virtual address space anda logical address in a logical address space. The VAT 454 retains thecorrespondence between virtual addresses and logical addresses. TheVATICB 455 indicates the recording position of the VAT 454. The VATICB455 is allocated to a sector at the trailing end of the area in whichthe data is recorded.

[0094] The recording information zone 111 includes a count unit 141 fordesignating the number of a valid registration unit, and a plurality ofregistration units including the first registration unit 142 and asecond registration unit 143. In the count unit 141, only a first countblock 171 indicating the identification number of the first registrationunit 142 is recorded. In the first registration unit 142, the firstregistration block 176 having an entry sector number 464 indicating thepositional information of the latest file structure area 431 isrecorded.

[0095] Data is not recorded in the second count block et seq. in thecount unit 141. Data is not recorded in the second count block et seq.in the first registration unit 142. Data is not recorded in the secondregistration unit 143 et seq.

[0096] 1.4 File Recording Processing

[0097]FIG. 5 shows a procedure of file recording processing forrecording a file on the optical disc 235. The file recording processingis performed by the information recording and reproduction apparatusshown in FIG. 2. Hereinafter, the steps shown in FIG. 5 will bedescribed in detail. In the following example, the AV file (AVfile-a),the AV file (AVfile-b), and a control file thereof are recorded on theoptical disc 235 having the data structure shown in FIG. 4.

[0098] (S501) The system control section 201 acquires positionalinformation 467 of an unallocated area from the unallocated space entry453 which has been read to the space management structure memory 253.The above-described operation of the system control section 201 isachieved by, for example, executing a control program built in thesystem control section 201 as the space management structure recordingmeans 251.

[0099] (S502) The system control section 201 allocates the unallocatedarea based on the positional information of the unallocated areaacquired in step (S501), and instructs the optical disc drive device 205to record data of an AV file (AVfile-a) 641 in the allocated area. Thesystem control section 201 further creates a file entry (AVfile-a) 642of the AV file (AVfile-a) 641, stores the file entry in the data memory221, and instructs the optical disc drive device 205 to record the fileentry in an area continuous from the area in which the data of the AVfile (AVfile-a) 641 has been recorded. Similarly, the system controlsection 201 instructs the optical disc drive device 205 to record dataof an AV file (AVfile-b) 643 and a file entry (AV file-b) 644 thereof inthe continuous areas. The above-described operations of the systemcontrol section 201 are achieved by, for example, executing a controlprogram built in the system control section 201 as the file recordingmeans 213. The optical disc drive device 205 records the above-mentioneddata at a predetermined position of the optical disc 235, and when therecording operation is completed, notifies the system control section201 of the completion of the recording operation.

[0100] (S503) The system control section 201 creates a basic filestructure, and stores the basic file structure in the basic filestructure memory 263 of the memory circuit 202. The system controlsection 201 further instructs the optical disc drive device 205 torecord the basic file structure, stored in the basic file structurememory 263, on the optical disc 235. The above-described operations ofthe system control section 201 are achieved by, for example, executing acontrol program built in the system control section 201 as the basicfile structure recording means 261. The optical disc drive device 205records the basic file structure at a predetermined position of theoptical disc 235, and when the recording operation is completed,notifies the system control section 201 of the completion of therecording operation.

[0101] (S504) The system control section 201 creates a space managementstructure, and stores the space management structure in the spacemanagement structure memory 253 of the memory circuit 202. At thispoint, positional information 666 of an unallocated area #1 (623) andpositional information 667 of an unallocated area #2 (621) areregistered in an unallocated space entry 652 in consideration of thecapacity of a VAT structure area 602 allocated in step (S505). Thesystem control section 201 further instructs the optical disc drivedevice 205 to record the space management structure, stored in the spacemanagement structure memory 253, on the optical disc 235. Theabove-described operations of the system control section 201 areachieved by, for example, executing a control program built in thesystem control section 201 as the space management structure recordingmeans 251. The optical disc drive device 205 records the spacemanagement structure at a predetermined position of the optical disc235, and when the recording operation is completed, notifies the systemcontrol section 201 of the completion of the recording operation.

[0102] (S505) The system control section 201 creates a VAT structure,and stores the VAT structure in the VAT structure memory 222 of thememory circuit 202. The system control section 201 further instructs theoptical disc drive device 205 to record the VAT structure, stored in theVAT structure memory 222, on the optical disc 235. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as the VAT structure recording means 212. The optical disc drivedevice 205 records the VAT structure at a predetermined position of theoptical disc 235, and when the recording operation is completed,notifies the system control section 201 of the completion of therecording operation.

[0103] (S506) The system control section 201 instructs the optical discdrive device 205 to record data in the recording information zone. Thedrive control section 231 creates a second registration block 177including an entry sector number (pointer information) indicating theposition of the trailing end of the latest file structure area and aversion number (version information) for identifying a validregistration block, stores the second registration block 177 in therecording information zone memory 273 of the memory circuit 232, andrecords the second registration block 177 at a predetermined position(an area continuous from the area in which the first registration block176 has been recorded) of the optical disc 235. The above-describedoperations of the drive control section 231 are achieved by, forexample, executing a control program built in the drive control section231 as the recording information zone recording means 271. When therecording operation is completed, the optical disc drive device 205notifies the system control section 201 of the completion of therecording operation.

[0104]FIG. 6 shows a structure of data recorded on the optical disc 235after the file recording processing is performed.

[0105] The volume structure area 101 has the volume structure recordedtherein. The detail of the volume structure is as described withreference to FIG. 4.

[0106] An AV file area 601 has the AV file (AVfile-a) 641, a file entry(AVfile-a) 642 thereof, the AV file (AVfile-b) 643, and a file entry(AVfile-b) 644 thereof recorded therein.

[0107] In a basic file structure area 632 of a latest file structurearea 631, the basic file structure is recorded. The basic file structureincludes a control file (Datafile) 645 having information relevant tothe AV files, a file entry (Datafile) 646 thereof, an AV directory(AVDir) 647, a file entry (AVDir) 648, a file set descriptor 649, a rootdirectory 650, and a file entry (root directory) 651 thereof. The AVdirectory (AVDir) 647 includes positional information of the file entry(AVfile-a) 642 of the AV file (AVfile-a) 641 and positional informationof the file entry (AVfile-b) 644 of the AV file (AVfile-b) 643.

[0108] The file set descriptor 649, the root directory 650, and the fileentry (root directory) 651 are recorded at a new recording position(logical address). By updating a logical address in the VAT 653describing the correspondence between the virtual addresses and thelogical addresses, the new recording position can be accessed using thesame virtual address. For example, the recording position of the fileset descriptor 649 designated by the logical volume descriptor 445 isdesignated using a virtual address. Even when the file set descriptor649 is recorded at a new recording position (logical address), the newrecording position of the file set descriptor 649 can be accessed byupdating the logical address in the VAT 653 describing thecorrespondence between the virtual addresses and the logical addresses.

[0109] In a space management structure area 622 of the latest filestructure area 631, the space management structure is recorded. Thespace management structure includes the unallocated space entry 652.

[0110] In the VAT structure area 602 of the latest file structure area631, a VAT structure is recorded. The VAT structure includes the VAT 653and the VATICB 654.

[0111] The recording information zone 111 includes the count unit 141for designating the number of a valid registration unit, and a pluralityof registration units including the first registration unit 142 and thesecond registration unit 143. In the count unit 141, only the firstcount block 171 indicating the identification number of the firstregistration unit 142 is recorded. In the first registration unit 142,the first registration block 176, and the second registration block 177having an entry sector number 663 indicating the positional informationof the latest file structure area 631 are recorded. It is recognizedthat the second registration block 177 is the latest registration blockhaving the valid entry sector number 663, by comparing a version number463 of the first registration block 176 and a version number 662 of thesecond registration block 177.

[0112] 1.5 Space Management Structure

[0113] Hereinafter, with reference to FIG. 1, the space managementstructure will be described.

[0114] A space management structure is a structure for managingpositional information of an unallocated area which is a continuous areaexisting in the volume space and in which data is recordable. The spacemanagement structure is necessarily recorded after some data is recordedon an optical disc.

[0115] An unallocated space entry 155, which is a space managementstructure, includes a descriptor tag 185 indicating that the entry is anunallocated space entry, and positional information of at least oneunallocated area existing in the volume space (in the example shown inFIG. 1, positional information 186 of an unallocated area #1, positionalinformation 187 of an unallocated area #2, positional information 188 ofan unallocated area #3, and positional information 189 of an unallocatedarea #4).

[0116] In order to record latest information while moving the latestinformation from an inner portion to an outer portion of the opticaldisc, positional information of unallocated areas is registered in theunallocated space entry 155, such that the positional information of theunallocated area external to and closest to the latest file structurearea 131 is registered in the innermost portion of the unallocated spaceentry 155 and then the positional information of the unallocated areaexternal to and next closest to the latest file structure area 131 isregistered in the second innermost portion of the unallocated spaceentry 155. When the positional information of the outermost unallocatedarea is registered in the unallocated space entry 155, the positionalinformation of unallocated areas is registered in the unallocated spaceentry 155, such that the positional information of the innermostunallocated area is registered in the next innermost portion of theunallocated space entry 155 and then the positional information of thenext innermost unallocated area is registered in the next innermostportion of the unallocated space entry 155.

[0117] In the example shown in FIG. 1, the unallocated area #1 (124) isexternal to and closest to the latest file structure area 131.Accordingly, the positional information 186 of the unallocated area #1(124) is registered in the unallocated space entry 155 as the firstpositional information.

[0118] Next, the positional information 187 of the unallocated area #2(125) located at the trailing end of the volume space is registered inthe unallocated space entry 155 as the second positional information.Next, the positional information 188 of the innermost unallocated area#3 (121) in the volume space is registered in the unallocated spaceentry 155 as the third positional information. Finally, the positionalinformation 189 of the unallocated area #4 (122) is registered in theunallocated space entry 155 as the fourth positional information. Inthis manner, the positional information of the unallocated areas isregistered in the unallocated space entry 155 in the order of theunallocated area #1 (124), the unallocated area #2 (125), theunallocated area #3 (121), and the unallocated area #4 (122).

[0119] By registering the unallocated areas in the unallocated spaceentry 155 in the above-described order and recording the data in theunallocated areas in the order of registration in the unallocated spaceentry 155, data can be recorded while moving the latest file structurearea on the optical disc. As a result, concentration of data rewrite ina specific area can be avoided, and thus occurrence of defects and datadestruction can be prevented.

[0120] In the case where the data recorded on the optical disc isdeleted or edited, an area which has been used so far becomesunnecessary. Positional information of the area which becomesunnecessary is registered in the unallocated space entry 155 aspositional information of a new unallocated area. Where in theunallocated space entry 155 the positional information of the newlyregistered unallocated area is to be located is calculated from thepositional information of the unallocated areas already registered inthe unallocated space entry 155. As a result, the positional informationof the new unallocated area is inserted at an appropriate position inthe unallocated space entry 155.

[0121] In this example, the location of registration of the positionalinformation of an unallocated area in the unallocated space entry 155 isdetermined based on the positions of the unallocated areas in the volumespace. Alternatively, at the time when an area becomes unnecessarybecause of deletion of data, the positional information of the areawhich becomes unnecessary may be registered at the trailing end of theunallocated space entry 155 as positional information of a newunallocated area. Still alternatively, the location of registration ofthe positional information of an unallocated area in the unallocatedspace entry 155 may be determined based on the time at which the areawhich becomes unnecessary is recovered as a new unallocated area. Bythis method also, concentration of data rewrite in a specific area canbe avoided.

[0122] The method of recording data from an inner portion to an outerportion according to the present invention is also applicable to a writeonce type disc.

[0123] In FIG. 8, the case where there is one control file for whichdata reliability is required is described. Alternatively, a plurality ofcontrol files may be recorded on the optical disc. In this case, thecontrol files may be recorded in the basic file structure area or the AVfile area. When the size of the control files is small or when thenumber of the control files is small, the control files are preferablyrecorded in the basic file structure area. The reason is that thecontrol files are easily accessed when recorded in the basic filestructure area. When the size of the control files is large or when thenumber of the control files is large, the control files are preferablyrecorded in the AV file area. The reason is that the size of the latestfile structure area can be kept small in this way. It is clear that byrecording the control files and file entries thereof in the AV filearea, concentration of data rewrite in a specific area at the time ofupdating the control files can be avoided.

[0124] It is possible to perform loop recording in a certain directionbased on the recording position information which indicates the nextrecording position designated by the entry sector number. The positionalinformation of the area where data is recordable is acquired from thespace management structure.

[0125] 1.6 Data Structure of the Recording Information Zone

[0126]FIG. 9 shows an exemplary data structure of the recordinginformation zone 111. In the example shown in FIG. 9, the recordinginformation zone 111 includes one count unit and 250 registration units.

[0127] The count unit includes 10 count blocks. Each of the 10 countblocks is, for example, formed as an ECC block which is the minimumrecording unit. Recorded in one of the 10 count blocks is identificationinformation which indicates which one of the 250 registration units isvalid (for example, the identification number of the registration unitto which the registration block having the valid entry sector numberrecorded therein belongs). The count unit is used for searching for avalid registration unit from the 250 registration units. Use of thecount unit allows the latest entry sector number to be acquired byreading only one valid registration unit, without reading all theregistration units.

[0128] Each count block is rewritten when the identification number ofthe valid registration unit is changed. Accordingly, the number of timesthe count block is rewritten is extremely small as compared to thenumber of times the registration block is rewritten.

[0129] The 10 count blocks included in the count unit are usedsequentially from the leading count block (first count block). One countblock is repeatedly used until the count block becomes unrecordable. Thecount block becomes unrecordable for reasons that, for example, data isrewritten by the number of times exceeding the rewritable number oftimes, and the count block is placed in a defect state due to adherenceof dust or the like. When the first count block becomes unrecordable, asecond count block is used. When the second count block becomesunrecordable, a third count block is used. In this manner, each countblock is rewritten until the count block becomes unrecordable. When thecount block becomes unrecordable, the next count block is used.Accordingly, search in the count blocks can be performed at higher speedas the number of times the data has been rewritten is smaller.

[0130] Each of the first registration unit through the 250thregistration unit includes 10 registration blocks. Each of the 10registration blocks is formed as an ECC block which is the minimumrecording unit. Each of the 10 registration blocks includes an area usedfor recording a version number (version information) indicating aversion of the registration block and an area used for recording anentry sector number (pointer information) indicating the trailing end ofthe latest file structure area.

[0131] Each time data is recorded in the latest file structure area, theversion number and the entry sector number are recorded in oneregistration block selected among the first to the tenth registrationblocks in one registration unit. Each time data is recorded in thelatest file structure area, the registration block, in which the versionnumber and the entry sector number are recorded, is changed. Forexample, when the data is recorded for the first time in the latest filestructure area, the version number and the entry sector number arerecorded in the first registration block; and data is recorded for thesecond time in the latest file structure area, the version number andthe entry sector number are recorded in the second registration block.In this manner, the version number and the entry sector number arerecorded in one registration block, sequentially from the firstregistration block to the tenth registration block. After the versionnumber and the entry sector number are recorded in the tenthregistration block, the version number and the entry sector number arerecorded in the first registration block again (data in the firstregistration block is overwritten). Then, again, the version number andthe entry sector number are recorded in one registration block,sequentially from the first registration block to the tenth registrationblock (data in each registration block is overwritten).

[0132] By recording the version number and the entry sector number inthe registration blocks one by one in this manner, concentration of datarewrite in a specific registration block can be avoided.

[0133] The position indicated by the entry sector number (pointerinformation) is not limited to the position of the trailing end of thelatest file structure area. The position indicated by the entry sectornumber (pointer information) may be any position (for example, apredetermined position) in any area (for example, the second informationrecording area) on the optical disc 235. The second informationrecording area may be an area where data is recordable by sequentialloop recording.

[0134] In this example, data is sequentially recorded repeatedly in eachof the 250 registration units. Namely, each of the 250 registrationunits is an example of the first information recording area in whichdata is recordable by sequential loop recording. By sequentiallyrecording data repeatedly in each of a plurality of divided areas inthis manner, the reliability of all the areas can be improved and thereading speed from each area can be raised.

[0135] The latest registration block is managed so as to have thelargest version number in the registration unit to which the latestregistration block belongs. The largest version number indicates thelatest version information. The entry sector number (pointerinformation) corresponding to the largest version number (latest versioninformation) is used as the valid entry sector number (valid pointerinformation).

[0136] In the example shown in FIG. 9, the third registration blockhaving version number (3) is the latest registration block. By causingthe registration unit to include 10 registration blocks in this manner,the latest registration block can be recognized only by reading datafrom the maximum of 10 registration blocks.

[0137] When one or more registration blocks become unusable in oneregistration unit, the next registration unit is used. For example, whenone or more registration blocks become unusable in the firstregistration unit (or when the version number of the registration blockreaches a certain value in the first registration unit), the secondregistration unit is used. The valid registration unit is identified bythe count unit. Accordingly, it is not necessary to search for all the250 registration units in order to identify the valid registration unit.

[0138] By providing a reserve recording information zone, in which acopy of the information recorded in the recording information zone 111is recorded, in the extended recording information zone 112 shown inFIG. 1, the reliability of the recording information zone 111 can beraised. In the case where the entry sector number cannot be read fromthe recording information zone 111 due to a reading error, the entrysector number can be read from the extended recording information zone112.

[0139] The information recording zone 111 need not be provided in thelead-in area or the lead-out area. The information recording zone 111may be provided in, for example, an area internal to the lead-in area.Alternatively, the information recording zone 111 may be provided in thevolume structure area 101. In such cases, the effect of preventingconcentration of data rewrite in a specific sector is provided. Thereason is that the position of the trailing end of the area in which theentry sector number is recorded can be indicated while sequential looprecording is performed.

[0140] The number of count blocks is not limited to 10. The number ofcount blocks may be any number of 1 or greater. The number ofregistration blocks is not limited to 10. The number of count blocks mayalso be any number of 1 or greater.

[0141] The number of registration units is not limited to 250. Thenumber of registration units may be any number of 1 or greater. When thenumber of registration units is 1, the count unit may be omitted, sinceit is not necessary to search for the valid registration unit. Namely,the recording information zone may be structured so as to include onlyone registration unit. When, for example, the number of registrationblocks is sufficiently large, the recording information zone can bestructured so as to include only one registration unit.

[0142] The recording unit in the recording information zone may be asector, and is not limited to an ECC block.

[0143] The optical disc may have identification information pre-recordedthereon which indicates that the recording information zone is allocatedto a predetermined area of the optical disc. This identificationinformation guarantees the high reliability of the optical disc, towhich the number of times of data rewrite is limited, at the time ofshipment of the optical disc. The reason is that by sequentiallyrecording data repeatedly using the recording information zone, thelimitation on the number of times of data rewrite can be compensatedfor.

[0144] A write once type disc can be regarded as a disc to which thenumber of times of data rewrite is limited to zero. Use of theabove-described recording information zone allows high-speed recognitionof the valid registration unit and the valid registration block recordedtherein even when the number of times of data rewrite is larger. Whenthe number of times of data rewrite is still larger so that all theregistration units in the recording information zone are used, furtherdata rewrite becomes possible by allocating a part of the extendedrecording information zone as a recording information zone.

[0145] It is also possible to provide a recording information zonehaving a more appropriate data structure to a write once type disc byincreasing the number of registration blocks in one registration unit orby increasing the number of count blocks in one count unit. For example,in the case where the number of count blocks in the count unit is equalto the number of registration units, the count block can be updated bythe same number of times the registration unit is updated. In the casewhere the number of count blocks in the count unit is larger than thenumber of registration units, even when the count block cannot beupdated due to a defect block or the like, the next count block can beused.

[0146] In order to avoid concentration of data rewrite in a specificcount block in the count unit, data may be sequentially recordedrepeatedly in the count unit. Namely, the count unit is an example ofthe third information recording area in which data is recordable bysequential loop recording. In this case, each count block included inthe count unit includes a version number (version information)indicating the version of the count block and an identification number(identification information) of the registration unit, like theabove-described registration block.

[0147] The latest count block is managed so as to have the largestversion number in the count unit. The largest version number indicatesthe latest version information. The identification number(identification information) corresponding to the largest version number(latest version information) is used as the valid identification number(valid identification information) of the valid registration unit.

[0148] By sequentially recording data repeatedly to the count unit andeach registration unit, old information remains in the count block andthe registration blocks. Thus, pre-update information (files) can bemaintained on the optical disc so that the information (files) can beused as backup information.

[0149] The above-described recording method is applicable to a writeonce type disc as well as a rewritable disc. Therefore, a commonrecording method can be useable for the rewritable disc and the writeonce type disc.

[0150] With the optical disc to which the number of times of datarewrite is limited, the registration blocks in the registration unit maybe set to be usable until the registration block becomes unrecordable,instead of sequential loop recording being performed. This shortens thereading time of data from the registration unit. The registration blockbecomes unrecordable for reasons that, for example, data is rewritten bythe number of times exceeding the rewritable number of times, and theregistration block is placed into a defect state due to adherence ofdust or the like. When the registration block becomes unrecordable, thenext registration block is used. By using one count block repeatedlyuntil the count block becomes unrecordable and also using oneregistration block repeatedly until the registration block becomesunrecordable, the reading time of data from the count unit can beshortened and the reading time of data from the registration unit canalso be shortened.

[0151] 1.7 File Reproduction Processing

[0152]FIG. 7 shows a procedure of file reproduction processing forreproducing a file recorded on the optical disc 235. The filereproduction processing is performed by the information recording andreproduction apparatus shown in FIG. 2. Hereinafter, the steps shown inFIG. 7 will be described in detail. In the following example, an AV file(AVfile-d) 158 is reproduced from the optical disc 235 having the datastructure shown in FIG. 1.

[0153] The optical disc 235 shown in FIG. 1 is obtained by deleting theAV file (AVfile-b) from the optical disc 235 having the data structureshown in FIG. 6 and recording an AV file (AVfile-c) and an AV file(AVfile-d).

[0154] (S701) When detecting that an optical disc is inserted to theoptical disc drive device 205, the drive control section 231 designatesthe position of the first count block 171 in the count unit 141 in therecording information zone 111.

[0155] (S702) The drive control section 231 determines whether thedesignated count block in the count unit 141 is in an unrecorded stateor not. When “yes”, the processing advances to step (S704); and when“no”, the processing advances to step (S703).

[0156] (S703) The drive control section 231 designates the position ofthe next count block in the count unit 141.

[0157] (S704) The drive control section 231 acquires an identificationnumber (identification information) of a registration block from thelast count block among the count blocks which are not in an unrecordedstate.

[0158] (S705) The drive control section 231 executes a reproductionoperation from the leading registration block in the registration unitdesignated by the identification number of the registration unit,thereby acquiring a version number (version information).

[0159] (S706) The drive control section 231 designates the position ofthe next registration block in the designated registration unit.

[0160] (S707) The drive control section 231 executes a reproductionoperation from the designated registration block. When the designatedregistration block designated in this reproduction operation is in anunrecorded state, or when the version number recorded in theregistration block is smaller than the version number acquired before,the processing advances to step (S709). Otherwise, the processingadvances to step (S708).

[0161] (S708) The drive control section 231 designates a position of thenext registration block in the designated registration unit. (S709) Thedrive control section 231 acquires an entry sector number recorded inthe latest registration block, and stores the entry sector number in therecording information zone memory 273.

[0162] The operations-of the drive control section 231 described insteps (S701) through (S709) are achieved by, for example, a controlprogram built in the drive control section 231 as the informationrecording and reproduction means 272.

[0163] (S710) The system control section 201 acquires the entry sectornumber stored in the recording information zone memory 273 of theoptical disc drive device 205 as information (pointer information)indicating the position of the trailing end of the latest file structurearea. The system control section 201 instructs the optical disc drivedevice 205 to reproduce a VATICB 157 recorded at the trailing end of thelatest file structure area. The above-described operations of the systemcontrol section 201 are achieved by, for example, executing a controlprogram built in the system control section 201 as the VAT structurereproduction means 215. The optical disc drive device 205 reads theVATICB 157 recorded at the trailing end of the latest file structurearea, and stores the VATICB 157 in the VAT structure memory 222 of thememory circuit 202.

[0164] Next, the system control section 201 decodes the positionalinformation of the VAT included in the read VATICB, follows a similarcontrol procedure to that for the VATICB so as to read a VAT 156recorded in the VAT structure area 108, and stores the VAT 156 in theVAT structure memory 222 of the memory circuit 202.

[0165] (S711) The system control section 201 reads a file entry (rootdirectory) 154 and a root directory 153 from a file set descriptor 152while converting the virtual address into a logical address using theVAT acquired in step (S710). The system control section 201 also reads afile entry (AVDir) 151 and an AV directory (AVDir) 150 which arerecorded in the same area as the file entry (root directory) 154 and theroot directory 153, as well as a file entry (Datafile) 149 and a controlfile (Datafile) 148 sequentially. Thus, the recording position of the AVfiles and relevant information is acquired. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as the basic file structure reproduction means 261.

[0166] (S712) Finally, the system control section 201 executes a readoperation of a file entry (AVfile-d) 159 and an AV file (AVfile-d) 158,thereby completing the file reproduction operation. The above-describedoperation of the system control section 201 is achieved by, for example,executing a control program built in the system control section 201 asthe file reproduction means 216.

[0167] In order to avoid data from becoming unreadable due to a readingerror during reproduction, a copy of the data may be recorded in anotherarea. The latest file structure area which is moved by sequentialrecording may be doubled, and the positional information of the doubledlatest file structure area may be designated in the recordinginformation zone. For example, as shown in FIG. 10, a reserve latestfile structure area 2103 and a main latest file structure area 2107 maybe designated based on a main entry sector number 2151 and a reserveentry sector number 2152 recorded in the registration blocks recorded inthe registration blocks recorded in a reserve recording information zone2101 and a main recording information zone 2102.

[0168] There is a possibility that data reproduction becomes impossibledue to the causing of scratches or dust after sequential recording withverify is performed. In order to allow the latest file to be read evenin such a case, the main latest file structure area 2107 and the reservelatest file structure area 2103 may be provided in the volume space andthe positional information thereof may be registered in the lead-in areaas the main entry sector number 2151 and the reserve entry sector number2152. Thus, data reproduction reliability is improved.

[0169] The information to be recorded in the reserve latest filestructure area 2103 is basically reserve information of the informationto be recorded in the main latest file structure area 2107. A VAT 2145to be recorded in a VAT structure area 2110 is a correspondence table ofthe virtual addresses and the logical addresses of the latest filestructure recorded in the main latest file structure area 2107. Bycontrast, a VAT 2135 to be recorded in a VAT structure area 2106 is acorrespondence table of the virtual addresses and the logical addressesof the latest file structure recorded in the reserve latest filestructure area 2103.

[0170] The positional information of the main latest file structure area2107 and the positional information of the reserve latest file structurearea 2103 may respectively be registered in the main recordinginformation zone 2102 and the reserve recording information zone 2101 ofthe lead-in area as the main entry sector number 2151 and the reserveentry sector number 2152. In this case, the reserve recordinginformation zone 2101 is an area where reserve information of theinformation registered in the main recording information zone 2102 isrecorded. The structure and method of use of the main or reserverecording information zone are similar to those of the recordinginformation zone shown in Example 1.

[0171] The positional information of the reserve latest file structurearea may be designated with an offset address from the main entry sectornumber. The offset address may be designated to be, for example, themain entry sector number−256, the main entry sector number−512, the mainentry sector number+256, or main entry sector number+512. The offsetvalue may be registered in the information recording zone.

[0172] Even in the case where the recording information zone is providedin the volume space instead of the lead-in area, the effect of thepresent invention is clearly provided. The entry sector number may berecorded in, for example, the volume space such as the volume structurearea 101. In this case also, substantially the same effect as providedwhen the entry sector number is recorded in the lead-in area isprovided.

[0173] The recording position information indicating the next recordingstart position, such as the entry sector number, allows data to berecorded repeatedly in a certain direction such that the areas in whichdata is rewritten are distributed throughout the information recordingarea of the information recording medium.

[0174] Registration of the reserve information of the informationrecorded in the main recording information zone may be performedindependently in the main recording information zone 2102 and thereserve recording information zone 2101. In this case, the count blockor the registration block is recorded using recording with verify so asto avoid defect areas. Therefore, the number of the count block or theregistration block which is the defect area is different between themain recording information zone 2102 and the reserve recordinginformation zone 2101.

[0175] In the reserve recording information zone 2101, copy informationmay be recorded in the same count block or the same registration blockas those in the main recording information zone 2102. In this case, itis not necessary to perform recording with verify in the reserverecording information zone 2101. Even in a defect state, recording isexecuted.

[0176] In this example, the information recorded in the reserve latestfile structure area is copy information of the main latest filestructure. For shortening the recording time, only the file structureupdated from the previous time of recording may be recorded in thereserve latest file structure area. When data is unreadable from themain latest file structure area, the reserve latest file structure andthe previous main latest file structure can be used to obtain the backupof the data. The previous main latest file structure can be acquired bydistinguishing the previous registration block based on the versionnumber and using the entry sector number recorded in the registrationblock.

[0177] As shown in FIG. 10, the latest file structure recorded in thevolume space is doubled. In the case where the positional information ofboth of the doubled latest file structure is included in the lead-inarea, the robustness of the file structure area which is indispensableto recording and reproduction of the file can be improved in theinformation recording medium, to which the number of times of datarewrite is limited, while performing sequential recording. By recordingdata, without fail, in the recording information zone which is an areadesignated for the positional information of the multiplied latest filestructure area, reproduction reliability of the disc is improved,despite the risk of reproduction becoming impossible due to the causesof scratches or dust.

[0178] It is clear that the latest file structure area and the entrysector number are both applicable to doubling, tripling and other typesof multiplication.

[0179] In the ECMA167 Standards, the file entry of the AV file isdefined as a part of the file structure. In this example, the file entryof the AV file is recorded in the AV file area for simplicity ofexplanation.

[0180] In the case of an information recording medium on which no AVfile is recorded, a control file may be recorded in the AV file area.Still, the effect of the present invention is clearly provided. In thiscase, the control file and the file structure thereof are sequentiallyrecorded in the volume space.

[0181] In this example, a file structure using the VAT structure isrecorded in the latest file structure area. In the latest file structurearea designated by the entry sector number, a file structure of otherfile systems such as a FAT file system or the like may be recorded. Evenwhen a file structure other than the VAT structure is used, the effectof avoiding concentration of data rewrite on a disc, to which the numberof times of data rewrite is limited, is provided as far as the entrysector number recorded in the recording information zone is used.

[0182] In this example, when a disc is inserted, the system records acontrol file in the basic file structure area in order to recognize theinformation recorded in a plurality of AV files. In the case where onlythe file recorded on the disc need be recognized, it is not necessary torecord the control and the file entry thereof in the basic filestructure area. Then, the basic file structure area is smaller and thusthe reading time is shortened. In the case where the basic filestructure area is recorded within one ECC block as the minimum readingunit, the driving device performs data read only once. In this manner,an information recording medium according to the present inventioncauses the data to be updated or recorded including the latest filestructure area to be moved from an inner portion to an outer portion.Therefore, data destruction or defect due to concentration of datarewrite is prevented and data reliability can be improved.

2. EXAMPLE 2

[0183] In Example 2, a method for sequentially recording an AV file inthe AV file area pre-allocated in the volume space and a defectmanagement method of information recorded in the latest file structurearea will be described.

[0184] AV data to be recorded in the AV file area needs to be recordedcontinuously time-wise, and thus is recorded without verify. Filemanagement information, such as the file set descriptor, and a controlfile are required to be reliable and thus is recorded with verify so asto guarantee the data reliability at the time of recording. In general,an AV file has a large data size, whereas a control file or filemanagement information have a small file size. AV data and non-AV datathus have different characteristics. An example in which an area usedfor recording AV data and an area used for non-AV data are separatedwill be described.

[0185] In the case where unallocated areas are managed in a table formas in Example 1, sequential recording is performed by defining the orderin which management information in the unallocated areas is registered.In Example 2, unallocated areas are managed using an improved bit mapwhich is recorded in the space management structure area, and sequentialrecording is performed in the AV file area in the volume space.

[0186] In the following description, a descriptor, a pointer and thelike which are recorded on the information recording medium as a volumefile structure have a data structure defined by the ECMA167 or UDF(Universal Disk Format) Standards unless otherwise described in detail.

[0187] 2.1 Data Structure of the Optical Disc

[0188]FIG. 11 shows an exemplary data structure of the optical disc 235.

[0189] The volume space has a volume structure area 101, a sparable filestructure area 1303, and an AV file area 1308 pre-allocated at fixedpositions thereof. The sparable file structure area 1303 includes aspace management structure area 1306 in a part of the latest filestructure area. In the space management structure area, an improved bitmap is to be recorded.

[0190] A bit map is a map showing a recording state of each of areas ofa certain unit, such as a sector or an ECC block. The recording state ofeach of areas of a certain unit is indicated by 0 in the case of anunrecorded state and by 1 in the case of a recorded state. A collectionof bits showing the recording states of all the sectors is referred toas a bit map. In Example 2, a bit map shows a recording state of a unit.An advantage of performing management of unallocated areas with a bitmap is that since the unallocated areas are designated using a bit foreach of areas to be managed, the size of the bit map is fixed.

[0191] A “unit” is a unit for managing recording including one or moresectors. In this example, one unit includes about 5000 sectors.

[0192] The lead-in area has a recording information zone 111 allocatedthereto. The recording information zone 111 includes a spare designationinformation area 1302 including a spare unit number 1310 and spare areaaddress information 1311. In the spare designation information area, alatest file structure area 1304 is substituted for by a sparable area1307 of the sparable file structure area 1303 or other units. Thus, whendata rewrite is concentrated in the latest file structure area 1304 ofthe sparable file structure area 1303 or when the entire area becomesunrecordable, such substitution prevents the medium from becomingunrecordable entirely. As a result, data can be recorded in the latestfile structure area.

[0193] 2.2 File Recording Processing

[0194]FIG. 13 shows a procedure of file recording processing forrecording a file on the optical disc 235. The file recording processingis performed by the information recording and reproduction apparatusshown in FIG. 2. Hereinafter, the steps shown in FIG. 13 will bedescribed in detail.

[0195] (S1501) The system control section 201 acquires a start unitnumber 1330 from the leading end of the improved bit map 1313 which hasbeen read into the space management structure memory 253. Theabove-described operation of the system control section 201 is achievedby, for example, executing a control program built in the system controlsection 201 as the space management structure recording means 251.

[0196] (S1502) The system control section 201 instructs the optical discdrive device 205 to record the AV file (AVfile-d) 146 sequentially fromunit #40 designated by the start unit number 1330. The above-describedoperation of the system control section 201 is achieved by, for example,executing a control program built in the system control section 201 asthe file recording means 213.

[0197] (S1503) The system control section 201 updates the file structureincluding management information of the recorded AV file (AVfile-d), andinstructs the optical disc drive device 205 to record the updated filestructure in the latest file structure area 1304. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as the basic file structure recording means 261.

[0198] At this point, when a write error is returned from the opticaldisc drive device 205 for the reason that the latest file structure area1304 of the sparable file structure area 1303 becomes unrecordable dueto concentration of data rewrite, scratches or dust, the system controlsection 201 updates the basic file structure so as to change therecording position and issues an instruction that the recording shouldbe performed in the sparable area 1307.

[0199] When another write error is returned from the optical disc drivedevice 205 for the reason that the sparable area 1307 becomesunrecordable due to concentration of data rewrite, scratches or dust,the system control section 201 issues an instruction that a basic filestructure area should be recorded in which the recording position ischanged to unit #56. In this manner, unit #56, which is the nextrecording start unit for performing recording sequentially in the AVfile area 1308, can be used as a sparable file structure area. In thismanner, when a write error occurs while data is being recorded in thelatest file structure area, the data recorded in the latest filestructure area is updated and recorded in an unrecorded sparable area.When there is no unrecorded area in the sparable area, the start unitnumber is used to allocate a sparable file structure area to anunallocated unit, and data recorded in the latest file structure area isupdated and recorded at the leading end of the sparable file structurearea. When the sparable file structure area is allocated to theunallocated unit, a predetermined size of sparable area is arranged inan unrecorded state. Therefore, even when a write error occurs whiledata is being recorded in the latest file structure area, sparerecording is realized.

[0200] The drive control section 232 instructs the recording andreproduction means 234 to record the basic file structure in unit #56.When the recording is completed, “56” is recorded in a spare unit number1410 in the recording information zone 111 in the lead-in area, and theaddress information of the latest file structure area is recorded inspare area address information 1411. Then, the drive control section 232notifies the system control section 201 of completion of the processing.

[0201] (S1504) The system control section 201 creates an improved bitmap 1412 reflecting the state of an unallocated area of the disc, andrecords the improved bit map 1412 in a space management structure area1403. The above-described operations of the system control section 201are achieved by, for example, executing a control program built in thesystem control section 201 as the space management structure recordingmeans 251.

[0202] At this point, the unit number of 57 which indicates the firstunallocated area after the recorded unit is registered as the start unitnumber at the leading end of the improved bit map. By this processing,the bits of units #40 through #56, which indicate the recording statesof these units having data recorded therein, are changed to “1”, whichindicates “recorded”.

[0203]FIG. 12 shows a structure of data recorded on the optical disc 235after the file recording processing is performed on the optical disc 235having the data structure shown in FIG. 11.

[0204] In this example, the second cycle of the sequential recordingperformed in an inner portion to an outer portion in the AV file area isdescribed. In an information recording medium to which the number oftimes of data rewrite is limited, the recording start position isdesignated by a start unit number. Therefore, sequential recording canbe performed repeatedly in the AV file area, from an inner portion to anouter portion of the disc.

[0205] The next recording start position may be designated by an addressinstead of a start unit number. When the next recording start positionis designated by an address, the recording start position can bedesignated in more detail as compared to the case of using a start unitnumber. Instead of the next recording start position, the previousrecording end position may be designated.

[0206] In this example, the unallocated areas in which AV files can berecorded are designated unit by unit, and the areas in which the AVfiles are recorded are designated logical sector by logical sector. Forsimplification, the areas in which the AV files are recorded may also bedesignated unit by unit.

[0207] In this example, only the AV files are recorded in the AV filearea. As described in Example 1, a file entry of the AV file may also berecorded in the AV file area.

[0208] In the case where the size of the control file is excessivelylarge or the number of control files is excessively large, the controlfile(s) and file entry (entries) thereof may be recorded in the AV filearea. In this manner, data rewrite is prevented from concentrating in aspecific area when the control files are updated.

[0209] For recording data in the volume structure area and the latestfile structure area, recording with verify is performed. For recordingdata in the AV file area, recording without verify is performed.“Recording with verify” refers to a recording method by which it isconfirmed that data can be read after the recording is performed.“Recording without verify” refers to a recording method by which it isnot confirmed that data can be read after the recording is performed.

[0210] In this example, the latest file structure area aftersubstitution is managed by the system control section 201. In a systemin which the spare area is managed by the drive control section 231, themanagement may be performed by a system referred to as “linearreplacement”. “Linear replacement” refers to a system by which the drivecontrol section manages the correspondence between logical addressinformation designated by the system control section and physicaladdress information of the address at which data is actually recorded.By this system, reproduction is performed not by accessing the indicatedlogical address but by reading data from the corresponding physicaladdress. In this system, the system control section need not update therecording position information for the basic file structure inaccordance with the substitution.

[0211] In the case where two-stage substitution processing is performedincluding substitution by a sparable area and allocation of a sparablefile structure area to a unit, even when the number of data rewriteunexpectedly increases in a medium having a defined size of filestructure area or AV file area, recording to and reproduction from themedium can be performed without interruption.

[0212] 2.3 File Reproduction Processing

[0213]FIG. 14 shows a procedure of file reproduction processing forreproducing a file recorded on the optical disc 235. The filereproduction processing is performed by the information recording andreproduction apparatus shown in FIG. 2. Hereinafter, the steps shown inFIG. 14 will be described in detail. In the following example, the AVfile (AVfile-d) 158 is reproduced from the optical disc 235 having thedata structure shown in FIG. 12.

[0214] (S1601) When an optical disc is inserted to the optical discdrive device 205, the drive control section 231 reads a spare unitnumber 1410 and spare area address information 1411 from the sparedesignation information area 1302 of the recording information zone, andnotifies the system control section 201 of the spare unit number 1410and the spare area address information 1411. The above-describedoperations of the system control section 201 are achieved by, forexample, executing a control program built in the system control section201 as the information recording and reproduction means 272.

[0215] The system control section 201 determines whether the read spareunit number 1410 is 0 or 1. When the number is 0, the processingadvances to step (S1603). Otherwise, the processing advances to step(S1602).

[0216] (S1602) The system control section 201 reproduces a basic filestructure from a basic file structure area of the latest file structurearea recorded in a unit having the designated unit number, based on thespare unit number and the spare area address information.

[0217] In the example shown in FIG. 12, the spare unit number 1410 is56. Accordingly, a basic file structure is read from a basic filestructure area 1402 of a latest file structure area 1401 recorded inunit #56.

[0218] (S1603) The system control section 201 reproduces a basic filestructure from a basic file structure area of the latest file structurearea recorded in a pre-allocated sparable file structure area, based onthe spare address information.

[0219] In the example shown in FIG. 11, the spare unit number 1410 is 0.Accordingly, a basic file structure is read from a basic file structurearea 1305 of the latest file structure area 1304 recorded in thesparable file structure area 1303.

[0220] The operations of the system control section 201 described insteps (S1602) and (S1603) are achieved by, for example, executing acontrol program built in the system control section 201 as basic filestructure reproduction means 262.

[0221] (S1604) The system control section 201 decodes the basis filestructure and reproduces the intended AV file (AVfile-d) 158. Theabove-described operations of the system control section 201 areachieved by, for example, executing a control program built in thesystem control section 201 as file reproduction means 216.

[0222] In general, the size of AV files is larger than the size ofcontrol data. Therefore, in this example, the AV files are managed unitby unit. Accordingly, the recording position information of an AV filecan be easily designated using a unit number instead of a logical sectornumber.

[0223] In this example, unallocated areas are registered in the bit mapin the order from an inner portion to an outer portion of the disc.Accordingly, sequential loop recording can be performed by designatingthe next recording position with a start unit number. By the method ofmanaging unallocated areas using a table as shown in Example 1,unallocated areas are registered in the table in the order from an innerportion to an outer portion of the disc, and the next recording startposition is designated by an entry sector number.

[0224] In Example 2, the sparable file structure area is pre-allocatedin the volume space. Therefore, data rewrite of the latest filestructure is concentrated. However, the spare designation informationarea including the recording information zone allows data to be recordedat a different location. As a result, the medium is prevented frombecoming entirely unusable.

[0225] By use of a start unit number provided in the improved bit mapwhich is recorded in the space management structure area, a recordingstart position in the AV file area can be acquired. This allows the AVfiles to be recorded sequentially while avoiding concentration of datarewrite. In the case where the start unit number is registered at theleading end of the space management structure, recording can be startedfrom the recording start position immediately after the space managementstructure is acquired.

[0226] In Example 1, data is sequentially recorded in the latest filestructure area. In Example 2, data is rewritten in the latest filestructure area each time the data is updated. Recording of the latestfile structure area may be performed sequentially and repeatedly in thesparable file structure area, using, as described in Example 1, emptyarea information recorded in the space management structure area andspare address information which indicates the position allocated as thelatest file structure area. For example, recording may be performed inthe following manner for updating data. Up to the trailing end of thesparable file structure area, an unallocated area is searched for in acertain direction (for example, from an inner portion to an outerportion of the disc) from a position continuous from the position of thearea to which the latest file structure area is allocated (i.e., theposition indicated by the pointer information). The area is allocatedbased on the search result, and data of the latest file structure areais recorded in the allocated area. In the case where the latest filestructure area is recorded at the trailing end of the sparable filestructure area, an unallocated area is searched for in a certaindirection from the leading end of the sparable file structure area. Thearea is allocated based on the search result, and data of the latestfile structure area is recorded in the allocated area.

[0227] As can be understood, the sparable file structure area isstructured such that another area (for example, the latest filestructure area) can be allocated to a part of the sparable filestructure area. The different area (for example, the latest filestructure area) allocated to the part of the sparable file structurearea is structured so as to be movable in the sparable file structurearea. Thus, data can be recorded repeatedly in a certain direction suchthat latest file structure areas are distributed throughout the sparablefile structure area.

[0228] In Example 2, sequential loop recording can be performed both inthe AV file area and the sparable file structure area. Thus,concentration of data rewrite in any specific area throughout the discis avoided. By dividing an area into a plurality of areas and performingsequential loop recording in each of the divided areas, data reliabilitycan be improved and the reading speed of an intended file can be raised.

3. EXAMPLE 3

[0229] In Example 3, AV files are sequentially recorded in the AV filearea, using a table for simultaneously managing the recording positionof a file and the position of an unallocated area, such as a FAT filesystem applied to a hard disc or the like.

[0230] When constructing a system compatible with a hard disc, the harddisc and the optical disc can be handled by one file system byintroducing the FAT file system to the optical disc.

[0231] In the following description, a descriptor, a pointer and thelike which are recorded on the information recording medium as a volumefile structure have a data structure defined by the ECMA167 or UDF(Universal Disk Format) Standards unless otherwise described in detail.

[0232] 3.1 Data Structure of the Optical Disc

[0233]FIG. 15 shows an exemplary data structure of the optical disc 235.

[0234] The volume space has a system area 1701, a latest file structurearea 1702, and an AV file structure area 1703.

[0235] The latest file structure area 1702 includes a FAT (FileAllocation Table) area 1704, a root directory area 1705, an AV directoryarea 1706, and a data file area 1707. In the FAT area 1704, FAT isrecorded, which has chain information on the recording positions ofdirectories and files and information on the recording state ofclusters.

[0236] The FAT is a table in which cluster recording information havingrecording information for each of clusters is recorded. The number ofpieces of cluster recording information recorded corresponds to thenumber of clusters. In a directory entry recorded in the root directoryarea 1705 and an AV directory area 1706, start cluster numbers of thedirectory and the file are registered. In the example shown in FIG. 15,a directory entry (AVfile-a) 1713 has start cluster number 1 of an AVfile (AVfile-a) 144. The FAT chain information includes cluster #1 as astart cluster of the AV file (AVfile-a) and cluster number 2, which isthe number of the next cluster, registered thereto. In this manner, theAV file (AVfile-a) is reproduceable by following the chain information.In the “value” section of the chain information, “EOF” indicates thetrailing end of the file and is, for example, FF8 (hexadecimal).

[0237] A cluster is a unit for recording management including one ormore sectors. In this example, one cluster includes about 5000 sectors.

[0238] 3.2 File Recording Processing

[0239]FIG. 16 shows a procedure of file recording processing forrecording a file on the optical disc 235. The file recording processingis performed by the information recording and reproduction apparatusshown in FIG. 2. Hereinafter, the steps shown in FIG. 16 will bedescribed in detail.

[0240] (S1801) The system control section 201 reads a FAT from the FATarea 1704 at the leading end of the latest file structure area 1702,searches for a cluster number marked as starting point information, andsequentially acquires information on unallocated areas from the markedcluster number in an ascending order. The above-described operations ofthe system control section 201 are achieved by, for example, executing acontrol program built in the system control section 201 as the spacemanagement structure recording means 251.

[0241] (S1802) The system control section 201 sequentially records AVfiles from the designated starting point cluster. The above-describedoperation of the system control section 201 is achieved by, for example,executing a control program built in the system control section 201 asthe file recording means 213.

[0242] (S1803) The system control section 201 records, in the latestfile structure area, the AV directory area including the information onthe recorded AV file, the root directory area, the data files, and theFAT area. In the FAT recorded at this point, the cluster information,having the chain information and the starting point information of therecorded files, is updated. For example, in FIG. 15 showing the datastructure after the AV file (AVfile-c) 146 is recorded, the nextrecording starting point is cluster #56. Therefore, “1” is registered asthe starting point information of the cluster #56 of the FAT 1710. Theabove-described operations of the system control section 201 areachieved by, for example, executing a control program built in thesystem control section 201 as the basic file structure recording means261.

[0243] In this example, the second cycle of the sequential recordingperformed in an inner portion to an outer portion in the AV file area isdescribed. In an information recording medium to which the number oftimes of data rewrite is limited, sequential loop recording is performedin a similar manner in the AV file area in the first and subsequentcycles.

[0244] For simplicity of explanation, the control file, which is a datafile, is recorded as a part of the latest file structure area. Thecontrol file is not supplied with any cluster number and is managed bythe logical sector number. Alternatively, a data file may be recorded inthe cluster in the AV file area as a data file for controlling theinformation of an AV file.

[0245] In Example 3, the AV directory area, the root directory area, thedata files, and the FAT area are recorded in the latest file structurearea in accordance with the basic file structure recording means 261.The FAT has a structure having a function of a space managementstructure, but also performs file management. Therefore, the FAT ishandled by the basic file structure recording means and the basic filestructure reproduction means.

[0246] In Example 3, the starting point information for performingsequential recording is recorded with bit 1. It is clear that thestarting point information may be indicated with other values such asFFh.

[0247] In Example 3, the start position of sequential recording can beacquired also using a data structure, such as a FAT, in which theinformation on unallocated areas and the chain information of files aremanaged by the same table. In this case also, AV files can besequentially recorded while avoiding concentration of data rewrite inthe AV file area.

[0248] In Example 2, the start unit number is registered at the leadingend of the space management structure. In Example 3, the starting pointinformation is registered as a part of the information on each clusterin the space management structure. In the case where the starting pointinformation is registered in reserved bytes of information on eachcluster, this file system can be compatible with existing computeroperating systems without extending the FAT Standards.

[0249] The two-stage defect management method described in Example 2 isapplicable to the latest file structure area including the FAT area inthis example.

[0250] The cluster, which becomes unusable due to occurrence of a defectin the AV file area, may be registered in the FAT 1710 in the FAT area1704. In this case, FFh is registered as, for example, the value of thestarting point information.

4. EXAMPLE 4

[0251] In Example 4, an exemplary defect management method when an AVfile, a control file, and a volume file structure are sequentiallyrecorded on a disc to which the number of times of data rewrite islimited will be described.

[0252] Even in the case where, as in Example 1, occurrence of a defectarea is prevented by avoiding concentration of data rewrite in aspecific area using sequential recording, the number of defect areasincreases as the disc is used an increasing number of times.

[0253] In the following description, a defect area includes an area inwhich data cannot be recorded or reproduced, and a minimum unit thereofis 1 ECC block.

[0254] 4.1 Data Structure of the Optical Disc

[0255]FIG. 17 shows an exemplary data structure of the optical disc 235.

[0256] The volume space includes defect areas 1902, 1906, 1906 and 1910.A defect list structure area 1908 is allocated in which these defectareas are to be registered. In the defect list structure area 1908, asystem stream directory 1923 in which a data structure for the system isto be registered, a file entry 1924 thereof, and a file entry 1925 of anon-allocatable space stream are recorded. The non-allocatable spacestream is a data structure defined for registering a defect area or anarea in which a volume file structure cannot be allocated. In thisexample, the non-allocatable space stream is used for registering thepositional information of a defect area.

[0257]FIG. 18 shows a procedure of file recording processing forrecording a file on the optical disc 235. The file recording processingis performed by the information recording and reproduction apparatusshown in FIG. 2. Hereinafter, the steps shown in FIG. 18 will bedescribed in detail. In the following example, the AV file (AVfile-c) isrecorded on the optical disc 235 having the data structure shown in FIG.17.

[0258] (S2001) The system control section 201 records the AV file(AVfile-c) in unallocated areas sequentially from the unallocated areahaving the designated entry sector number. When the defect area 1906 isdetected while recording the AV file, the system control section 201skips the defect area and continues the recording in the nextunallocated area. Accordingly, the areas in which the AV file isactually recorded are a first extent 1921 of an AV file area 1905 and asecond extent 1922 of an AV file area 1907. The above-describedoperation of the system control section 201 is achieved by, for example,executing a control program built in the system control section 201 asthe file recording means 213.

[0259] (S2002) The system control section 201 creates a file entry(AVfile-c) 147 having positional information of the first extent 1921and the second extent 1922 (in which the AV file (AVfile-c) is recorded)registered therein. The system control section 201 then stores the fileentry (AVfile-c) 147 in the basic file structure memory 235 of thememory circuit 263.

[0260] (S2003) The system control section 201 records a control file(Datafile) 148 on a subsequent unallocated area. When a defect area isdetected while recording the control file, the system control section201 skips the defect area and continues the recording in the nextunallocated area, like in the case of the recording of the AV filedescribed in step (S2001).

[0261] (S2004) The system control section 201 creates the file entry(Datafile) 149 in which the positional information of the area (extent),in which the control file (Datafile) 148 is recorded, is registered. Thesystem control section 201 then stores the file entry (Datafile) 149 inthe basic file structure memory 235 of the memory circuit 263. In thecase where the control file is recorded in a plurality of extents due toa defect area being detected, all the extent position information isregistered when the recording position information of the control fileis registered, like in the case of the AV file.

[0262] (S2005) The system control section 201 creates a system streamdirectory 1924, which is a defect list structure, and the file entry1923 thereof, and also creates the file entry 1925 of an allocated spacestream in which the positional information of a defect area detected inthe volume space is registered. The system control section 201 storesthe file entry 1925 in the basic file structure memory 235.

[0263] In addition, the system control section 201 creates theunallocated space entry 1925 in which positional information of theunallocated space is registered, excluding the unallocated areasrecorded in the file recording processing and positional information ofthe defect areas detected in the file recording processing. The systemcontrol section 201 then stores the unallocated space entry 1925 thereofin the basic file structure memory 235.

[0264] Concurrently, the system control section 201 creates the AVdirectory (AVDir) 150 including information of the recorded AV file andthe control file, the file set descriptor 152, the root directory 153,the file entry 154 of the root directory, the file entries 145 and 159in which positional information and attribute information of recorded AVfiles (AVfile-a) 144 and (AVfile-d) 158 are registered, the VAT 156, andthe VATICB 157. The system control section 201 stores these data in thebasic file structure memory 235.

[0265] (S2006) The system control section 201 records the basic filestructure, the defect list structure, the space management structure 123and the VAT structure, which are created in steps (S2002), (S2004) and(S2005), in the latest file structure area 131.

[0266] (S2007) In the case where a defect area is detected while data isbeing recorded in the latest file structure area 131, the processing ofsteps (S2008) et seq. is executed. When the recording is completed withno defect being detected, the file recording processing is terminated.

[0267] (S2008) The system control section 201 updates the defect liststructure and the registration information on the space managementstructure. In the non-allocatable space stream which is a defect liststructure, positional information on a newly detected defect area isregistered. From the non-allocatable space stream which is a spacemanagement structure, the positional information on a newly detecteddefect area is eliminated.

[0268] (S2009) The system control section 201 designates the subsequentunallocated area in order to record data in the updated latest filestructure.

[0269] The operations of the system control section 201 described insteps (S2001) through (S2009) are achieved by, for example, executing acontrol program built in the system control section 201 as the basicfile structure recording means 261.

[0270] In the recording processing of the AV file in this example, anarea, from which an error report is returned for the reason that therecording cannot be completed while recording is performed withoutverify, is identified as a defect area.

[0271] In general, data to be recorded in the volume structure area andthe latest file structure area is recorded with verify, and data to berecorded in the AV file area is recorded without verify. Alternatively,the data to be recorded in the AV file area may be recorded with verify.The data to be recorded in the volume structure area and the latest filestructure area may be recorded without verify. The data to be recordedin the AV file area may be recorded with recognition that there is nodefect area, in order to save the time required for substitutionprocessing. In this case, a defect area is distinguished at the time ofreproduction of the file.

[0272] In order to change the defect management method in accordancewith the characteristics of the file, an area used for recording data towhich one defect management method is applied, and an area used forrecording data to which a different defect management method is applied,may be separated from each other.

[0273] An area from which the file cannot be reproduced may also beregistered as a defect area.

[0274] The positional information of a defect area registered as anon-allocatable space stream is used for re-formatting the medium.Accordingly, it is necessary to maintain the content of thenon-allocatable space stream until the medium is re-formatted.

[0275] The positional information of the detected defect area may berecorded outside the volume space. For example, such positionalinformation may be managed in the registration block of the recordinginformation zone in Example 1.

[0276] The method described in this example may be applied to Example 3.When performing defect management, data is recorded while a defect areabeing skipped, and defect information is registered in the FAT.

[0277] As described above, in this example, while sequential recordingon a rewritable medium is repeated, recording in the subsequent area canbe performed while avoiding a detected defect area without substitution.Thus, in the case of a rewritable recording medium in which the amountof detected defects significantly changes in accordance with theconditions of use, it is not necessary to obtain a spare area in advanceor to extend the spare area when there is a shortage thereof. The areaof the medium can be effectively used.

5. EXAMPLE 5

[0278] In Example 5, regarding a disc to which the number of time ofdata rewrite is limited as a result of the density being increased, anexemplary data structure for an entry sector number used for performingsequential loop recording from an inner portion to an outer portion ofthe disc, and an exemplary update method thereof, will be described.

[0279] In this example, an entry sector number is recorded in the volumespace which is managed by the file system, not in the recordinginformation zone.

[0280] In Example 1, the recording information zone includes a countunit and a plurality of registration units, so that the reliability ofthe entry sector number of the disc to which the number of times of datarewrite is limited is improved.

[0281] In this example, the reliability of the entry sector number canbe improved since the data structure defined by the ECMA167 is updatedstepwise, and the recording information zone is not necessary since theentry sector number is recorded. Thus, the techniques described in thisexample is applicable to general-purpose discs.

[0282]FIG. 19 is a data structure regarding an entry sector number whichis updated and recorded in the volume structure.

[0283] A function of an entry sector number 3032 is the same as thefunction described in the other examples. In FIG. 19, the entry sectornumber 3032 indicates the address of the VAT ICB 157 of the VATstructure area 104 in the latest file structure area 131. The entrysector number 3032 is recorded in a field saved for the processingsystem in a logical volume integrity descriptor 3031 in a logical volumeintegrity descriptor sequence 3011.

[0284] Recorded in the logical volume integrity descriptor is integrityinformation indicating whether or not the file structure recorded in thevolume space is in a correct state. Therefore, the reliability of theentry sector number can be further improved by recording the entrysector number in the logical volume integrity descriptor.

[0285] Positional information of the logical volume integrity descriptorsequence 3011 is recorded in a logical volume descriptor 3022 in avolume descriptor sequence 3010. The volume descriptor sequence 3010 isprovided for recording a descriptor regarding a volume. A primary volumedescriptor 3021 and a partition descriptor 3023 are recorded in thevolume descriptor.

[0286] Positional information of the volume descriptor sequence 3010 isrecorded in an anchor volume descriptor pointer 3041. The anchor volumedescriptor pointer is recorded in a fixed sector at a logical sectornumber 256. Although not shown, the anchor volume descriptor pointer isalso recorded in the logical sector of N-256, where N is the logicalsector number of the outermost portion of the volume space. Since theanchor volume descriptor pointer is recorded twice, even when one of thepointers cannot be read, the other anchor volume descriptor pointer canbe used.

[0287]FIG. 20 shows a procedure for updating and recording an entrysector number. An update method for an entry sector number will bedescribed.

[0288] (S3001) For the logical volume integrity descriptor sequence, anarea corresponding to, for example, 32 sectors is saved. The logicalvolume integrity descriptors are sequentially recorded from the leadingend the logical volume integrity descriptor sequence, and the finalvolume integrity descriptor recorded is recognized as a validdescriptor. The entry sector number is updated by recording a logicalvolume integrity descriptor in the subsequent logical sector. When thereis no more subsequent logical sector, ooh is recorded in all the logicalsectors in the logical volume integrity descriptor sequence, and thelogical volume integrity descriptor is recorded at the leading end ofthe logical volume integrity descriptor sequence.

[0289] (S3002) When recording a logical volume integrity descriptor, itis checked whether or not the logical sector to be recorded is a defectsector. When it is not a defect sector, the processing is terminated.When it is a defect sector, the processing advances to step (S3003),where a logical volume integrity descriptor sequence is newly saved inan empty area in the volume structure area, so that the logical volumeintegrity descriptor is recorded.

[0290] In this manner, in the case of a disc to which data rewrite islimited to 100 times, a logical volume integrity descriptor can berecorded 32×100 times, using the same logical volume integritydescriptor sequence.

[0291] When a logical volume integrity descriptor sequence is newlyallocated, it is necessary to record a logical volume descriptor formanaging the positional information of the logical volume integritydescriptor sequence.

[0292] (S3004) For the volume descriptor sequence, an area correspondingto, for example, 16 sectors is saved. The logical volume descriptor hasa field indicating a volume descriptor order number. When a plurality oflogical volume descriptors are recorded in the volume descriptorsequence, the logical volume descriptor having the largest volumedescriptor order number is valid. For recording the logical volumedescriptors, empty logical sectors are searched for from the leading endof the volume descriptor sequence. The logical volume descriptors arerecorded from the leading empty logical sector. When there is no emptylogical sector, all the old logical volume descriptors are recorded with00h so as to create an empty logical sector, and then the logical volumedescriptors are recorded from the leading empty logical sector.

[0293] (S3005) When recording a logical volume descriptor, it is checkedwhether or not the logical sector to be recorded is a defect sector.When it is not a defect sector, the processing is terminated. When it isa defect sector, the processing advances to step (S3006), where alogical volume descriptor sequence is newly saved in an empty area inthe volume structure area, so that the logical volume integritydescriptor is recorded together with a primary volume descriptor and apartition descriptor.

[0294] In this manner, in the case of a disc to which data rewrite islimited to 100 times, a logical volume descriptor can be recorded(16−2)×100 times, using the same logical volume descriptor sequence.

[0295] (S3007) When a volume descriptor sequence is newly allocated, ananchor volume descriptor pointer for managing the positional informationof the volume descriptor sequence is updated and recorded.

[0296] Since the entry sector number is updated and recorded stepwise inthis manner, recording can be performed (32×100)×((16−2)×100)×100 timesin total even on a disc to which the number of times of data rewrite islimited to 100.

[0297] The step for updating and recording may be varied in accordancewith the required number of times of data rewrite. It is clear that when1000 times of rewrite is sufficient, the entry sector number can berewritten in the same logical volume integrity descriptor sequence.

INDUSTRIAL APPLICABILITY

[0298] An information recording medium according to the presentinvention defines the order of use of unallocated areas registered in aspace management structure, and records data while moving a latest filestructure area from an inner portion to an outer portion. Thus, datadestruction or defect due to concentration of data rewrite is preventedand data reliability can be improved.

1. An information recording medium of which the number of times of datarewrite to an identical area is limited, the information recordingmedium comprising: a first information recording area to which data isrecordable by sequential loop recording; and a second informationrecording area, wherein: the first information recording area includes aplurality of blocks, each of the plurality of blocks includes an areafor recording version information indicating a version of the block andan area for recording pointer information indicating a position of thesecond information recording area, and pointer information correspondingto latest version information is used as valid pointer information. 2.An information recording medium according to claim 1, wherein the secondinformation recording area is an area in which data is recordable bysequential loop recording.
 3. An information recording medium of whichthe number of times of data rewrite to an identical area is limited, theinformation recording medium comprising: a plurality of firstinformation recording areas in which data is recordable by sequentialloop recording; a second information recording area; and a thirdinformation recording area for recording identification informationindicating which one of the plurality of first information recordingareas is valid, wherein: each of the plurality of first informationrecording areas includes a plurality of blocks, each of the plurality ofblocks includes an area for recording version information indicating aversion of the block and an area for recording pointer informationindicating a position of the second information recording area, and thepointer information corresponding to latest version information is usedas valid pointer information.
 4. An information recording mediumaccording to claim 3, wherein the identification information isrewritten in a specific area of the third information recording area,and when recording to the specific area becomes impossible, theidentification information is rewritten in an area in the thirdinformation recording area other than the specific area.
 5. Aninformation recording medium according to claim 3, wherein: the thirdinformation recording area is an area in which data is recordable bysequential loop recording, the third information recording area includesa plurality of blocks, each of the plurality of blocks includes an areafor recording version information indicating a version of the block, andthe identification information corresponding to latest versioninformation is used as valid identification information.
 6. Aninformation recording method for recording information on an informationrecording medium of which the number of times of data rewrite to anidentical area is limited, the information recording medium including afirst information recording area to which data is recordable bysequential loop recording, and a second information recording area,wherein the first information recording area includes a plurality ofblocks, the information recording method comprising the steps of:designating one of the plurality of blocks; and recording, in thedesignated block, version information indicating a version of thedesignated block and pointer information indicating a position of thesecond information recording area, wherein pointer informationcorresponding to latest version information is used as valid pointerinformation.
 7. An information recording method for recordinginformation on an information recording medium of which the number oftimes of data rewrite to an identical area is limited, the informationrecording medium including a plurality of first information recordingareas in which data is recordable by sequential loop recording, a secondinformation recording area, and a third information recording area,wherein each of the plurality of first information recording areasincludes a plurality of blocks, the information recording methodcomprising the steps of: recording, in the third information recordingarea, identification information indicating which one of the pluralityof first information recording areas is valid; designating one of theplurality of blocks included in the valid first information recordingarea; and recording, in the designated block, version informationindicating a version of the designated block and pointer informationindicating a position of the second information recording area, whereinpointer information corresponding to latest version information is usedas valid pointer information.
 8. An information recording apparatus forrecording information on an information recording medium of which thenumber of times of data rewrite to an identical area is limited, theinformation recording medium including a first information recordingarea to which data is recordable by sequential loop recording, and asecond information recording area, wherein the first informationrecording area includes a plurality of blocks, the information recordingapparatus comprising: means for designating one of the plurality ofblocks; and means for recording, in the designated block, versioninformation indicating a version of the designated block and pointerinformation indicating a position of the second information recordingarea, wherein pointer information corresponding to latest versioninformation is used as valid pointer information.
 9. An informationrecording apparatus for recording information on an informationrecording medium of which the number of times of data rewrite to anidentical area is limited, the information recording medium including aplurality of first information recording areas in which data isrecordable by sequential loop recording, a second information recordingarea, and a third information recording area, wherein each of theplurality of first information recording areas includes a plurality ofblocks, the information recording apparatus comprising: means forrecording, in the third information recording area, identificationinformation indicating which one of the plurality of first informationrecording areas is valid; means for designating one of the plurality ofblocks included in the valid first information recording area; and meansfor recording, in the designated block, version information indicating aversion of the designated block and pointer information indicating aposition of the second information recording area, wherein pointerinformation corresponding to latest version information is used as validpointer information.
 10. An information reproduction method forreproducing information recorded on an information recording medium ofwhich the number of times of data rewrite to an identical area islimited, the information recording medium including a first informationrecording area to which data is recordable by sequential loop recording,and a second information recording area, wherein the first informationrecording area includes a plurality of blocks, and in at least one ofthe plurality of blocks, version information indicating a version of theblock and pointer information indicating a position of the secondinformation recording area are recorded, the information reproductionmethod comprising the steps of: designating one of the plurality ofblocks; and determining whether or not to acquire the pointerinformation recorded in the designated block in accordance with theversion information recorded in the designated block, wherein pointerinformation corresponding to latest version information is used as validpointer information.
 11. An information reproduction method forreproducing information recorded on an information recording medium ofwhich the number of times of data rewrite to an identical area islimited, the information recording medium including a plurality of firstinformation recording areas in which data is recordable by sequentialloop recording, a second information recording area, and a thirdinformation recording area, wherein each of the plurality of firstinformation recording areas includes a plurality of blocks, in at leastone of the plurality of blocks, version information indicating a versionof the block and pointer information indicating a position of the secondinformation recording area are recorded, and in the third informationrecording area, identification information indicating which one of theplurality of first information recording areas is valid is recorded, theinformation reproduction method comprising the steps of: acquiring theidentification information from the third information recording area;designating one of the plurality of blocks included in the valid firstinformation recording area which is indicated by the identificationinformation; and determining whether or not to acquire the pointerinformation recorded in the designated block in accordance with theversion information recorded in the designated block, wherein pointerinformation corresponding to latest version information is used as validpointer information.
 12. An information reproduction apparatus forreproducing information recorded on an information recording medium ofwhich the number of times of data rewrite to an identical area islimited, the information recording medium including a first informationrecording area to which data is recordable by sequential loop recording,and a second information recording area, wherein the first informationrecording area includes a plurality of blocks, and in at least one ofthe plurality of blocks, version information indicating a version of theblock and pointer information indicating a position of the secondinformation recording area are recorded, the information reproductionapparatus comprising: means for designating one of the plurality ofblocks; and means for determining whether or not to acquire the pointerinformation recorded in the designated block in accordance with theversion information recorded in the designated block, wherein pointerinformation corresponding to latest version information is used as validpointer information.
 13. An information reproduction apparatus forreproducing information recorded on an information recording medium ofwhich the number of times of data rewrite to an identical area islimited, the information recording medium including a plurality of firstinformation recording areas in which data is recordable by sequentialloop recording, a second information recording area, and a thirdinformation recording area, wherein each of the plurality of firstinformation recording areas includes a plurality of blocks, in at leastone of the plurality of blocks, version information indicating a versionof the block and pointer information indicating a position of the secondinformation recording area are recorded, and in the third informationrecording area, identification information indicating which one of theplurality of first information recording areas is valid is recorded, theinformation reproduction apparatus comprising: means for acquiring theidentification information from the third information recording area;means for designating one of the plurality of blocks included in thevalid first information recording area which is indicated by theidentification information; and means for determining whether or not toacquire the pointer information recorded in the designated block inaccordance with the version information recorded in the designatedblock, wherein pointer information corresponding to latest versioninformation is used as valid pointer information.